australasian quaternary association's submission to the ... · coastal environments. the views...

Submission Mo:

Date Received:

Australasian Quaternary Association's submission to the"Inquiry into climate change and environmental impacts on

coastal communities"

AuthorDr Craig Sloss (contact person): Secretary of the Australasian Quaternary AssociationDr Patrick Moss (President of the AQUA)Professor Colin Murray WallaceAdjunct Professor Henk Heijnis(On behalf of the AQUA executive)

OrganisationAustralasian Quaternary Association

Type of organisation (e.g. industry, government, not for profit, research provider)Professional association, not for profit, voluntary.

AddressFor the purpose of this submission the organisation's contact address is:

Dr Craig SlossLecture in GeosciencesSchool of Natural Resource SciencesQueensland University of TechnologyGPO Box 2434BRISBANE Q 4001ph: 61 7 3138 82610fax: 61 7 3 138 1535email: [email protected]

Declaration of InterestAustralasian Quaternary Association (AQUA) has an interest in the subject of the inquirybut does not have affiliations with the inquiry. In providing this information none of themembers of AQUA stand to gain individually. The submission is made with the desire toprovide the inquiry with a framework in which to assess the impact of sea level rise oncoastal environments. The views given are those of members of the group, but notnecessarily of all members and not the views of the organisations that employ them. I ammaking this submission on behalf of the AQUA executive.

AQUAs_Submission_to lnquiry_into_climate_change_and_environmental_impacts_on_coastal_communities-pm_comments.doc Page I

Australasian Quaternary Association

Australasian Quaternary Association's submission to the"Inquiry into climate change and environmental impacts on

coastal communities"

In t roduct ion and Purpose of the Submission:The United Nations-sponsored Intergovernmental Panel on Climate Change (IPCC — FourthAssessment) reported there has been a temperature increase of 0.4 — 0.7°C since 1950 andthat the average temperature is likely to increase by between 1.4 and 5.8°C by 2100. Thisclimate change is likely to impact ecosystems, agriculture, and the spread of disease. TheIPCC also warns that one of the most dangerous impacts of global warming is a dramatic risein sea level and an increase in the severity and frequency of storms and coastal flooding.Over the last century global sea level has risen by approximately 10 - 20 cm and is estimatedthat it may rise between 9 and 88 cm by 2100. In the Australian region we have already seena rise of 1.2 mm/yr between 1920 and 2000 (Church et al., 2004). However, the worst casescenario is that sea level may rise by as much as 6 - 12 m if global warming goes on unabatedand we see a collapse of the great ice sheets (Stern, 2006; ICPP, 2007). With 80% ofAustralia's population living in coastal zones such rises in sea level will result ininfrastructural and ecological destruction as well as significant loss of natural resources.

To truly grasp the implications that sea level rise can have on coastal environments it isfundamental to have an understating of how sea levels have changed in the past. It isimportant to understand that sea level is not static but that it has undergone numerous risesand falls throughout geological history. For example, there have been 30 - 40 oscillations insea level in excess of 120 m over the Quaternary period (last 2 Million years). Suchoscillations have had a significant influence on the sedimentation and geomorphic change inthe coastal zone over the longer term record. Most significant is the last fullinterglacial/glacial cycle (last 125,000 years) where dramatic and relatively rapid fluctuationsin sea level have shaped our coast as we know it today. From the geological record it isevident that there is an intrinsic link between sea level and coastal environments. However,we are now seeing a period of sea level change that could be potentially more rapid than atany time in our geological past. Understanding how coastal environments responded to sealevel change (and past extreme events such as tsunami and storm surge) is fundamental fordevelopment of any adaption or mitigation programs aimed at dealing with the impact ofclimate change.

Also fundamental to the development of any adaption or mitigation programs aimed atdealing with the impact of climate change on coastal communities is an understanding thatglobally past histories of sea level change have not been the same. In fact, there aresignificant variations between different regions. This will also be the case for future changesin sea level. Accordingly, we cannot rely on "global estimates" and "global responses" orresearch conducted overseas, but must conduct our own national and regional researchprograms into past sea level histories, as well as regional scale adaption and mitigationstrategies. It is this understanding of how and why sea level changes occur, and how suchchanges will affect coastal communities on a regional scale that is of utmost importance.With a national and regional understanding of the history of sea level change it is possible tomore accurately model potential impact of future fluctuations in sea level and therelationship between sea level and extreme events.

AQUAs_Submission_to lnquiry_into_climate_change_and_environmental_impacts_on_coastal_communities-pm_comments.doc

Who we are:The Australasian Quaternary Association (AQUA; http://www.aqua.org.au/) is anorganisation comprising over 200 academics, researchers and post-graduate students thataim to promote the discussion and dissemination of information and ideas within the variousdisciplines and interests relating to Quaternary studies. Quaternary studies are those thatrelate to the Quaternary Period which is the most recent subdivision of geological timecovering the last 2 million years up to the present day. This has been a period ofextraordinary changes in global environment as well as the period during which much ofhominid evolution and migration took place, and humans began to modify their environment.The primary emphasis of AQUA is the promotion of research and teaching activities in allareas of Quaternary studies and promotion of scientific communication within theAustralasian region in relation to Quaternary studies. This is accomplished through a stronginter-disciplinary approach that provides a breadth of expertise across the disciplines ofgeology, geomorphology, climatology, biogeography, ecology and archaeology. Accordingly,AQUA provides workshops, conferences and field meetings that aim to develop a holisticview on Quaternary studies, including long and short-term climate change. In summary theobjectives of Australasian Quaternary Association are to:

provide a forum in Australasian region for the interchange of multi-disciplinaryknowledge and skills in all fields relating to Quaternary studies;promote the dissemination of information and ideas relating to the Quaternaryperiod;arrange or sponsor meetings, conferences and symposia on subjects consistent withthe objectives of the Association;promote the publication of technical information in the disciplines of QuaternaryStudies;encourage the interchange of those engaged in Quaternary Studies within Australiaand overseas; andencourage education, training, research and development in Quaternary Studies.

As a national multi-disciplinary organisation AQUA can assist in coordinating and collatingthe various aspects of research that are investigating how past climate change and extremeevents have impacted on coastal environments. As a national organisation we can alsoprovide a means for the government to communicate with the scientific community andfacilitate coordinated efforts for future research in to climate and sea level change.

Accordingly, it is the purpose of the submission from the Australasian QuaternaryAssociation to provide the inquiry with:

the fundamental background into long-term fluctuations in sea level;an understanding of the causes of natural variations in sea level;an understanding of the causes of natural hazards such as storm surge and tsunami;an understanding of the how the current trends in sea level change differ from thoseobserved in the geological record;facilitate, coordinate and report on research that is developing an understanding ofhow such changes in sea level (and the impact of extreme events) effect coastalenvironments on national and regional scales;a database of researchers investigating the impact of climate change and extremeevents in coastal environments; anda means for greater communication between the government and scientificcommunity who are currently undertaking research into the impacts of climatechange.


To whom it may concern,

Please find enclosed a signed hard copy of the AQUA submission to the "Inquiry intoclimate change and environmental impacts on coastal communities"

Thank you and please do not hesitate to contact me if you require any furtherinformation.

Dr Craig SlossLecturer in GeoscienceSchool of Natural Resource SciencesQueensland University of TechnologyGPO Box 2434BRISBANE Q 4001ph:61 7 3138 2610fax: 61 7 3138 1535email: c.sloss(5)qutedu.au

Secretary for the Australasian Quaternary Association (AQUA)email: Secretary(5)aqua.orq.au

Summary: Long-term climate change

Craig R. Slossa and Colin V. Murray-Wallaceb.

aSchool of Natural Resources, Queensland University of Technology, GPO Box 2434Brisbane 4001, Queensland, Australia

bSchool of Earth and Environmental Sciences, University of Wollongong, Wollongong, NSW 2522,Australia

THE QUATERNARY

The Quaternary is the most recent subdivision of geological time (the Quaternary Period)

which covers approximately the last 2 million years up to the present day. The Quaternary

Period can be subdivided into two epochs; the Pleistocene (2 Ma to 10 years ago) and the

Holocene (10 years ago to the present day). The Quaternary Period has been one of

extraordinary changes in the global environment as well as being the period during which

much of hominid evolution and migration took place. During the Quaternary there was a

series of step-like, sudden, changes in climatic conditions between cool phases with

expanding polar ice caps (glacials i.e. ice ages) and warm phases with a significant

contraction of polar ice caps (interglacials). The alternating expansion and contraction of the

great ice sheets resulted in significant fluctuations of sea level in excess of 130 m.

The glacial/interglacial cycle

During the Quaternary there were numerous rhythmic alterations from cold to warm

conditions, resulting in the conventional subdivision of the Quaternary into glacial and

interglacial stages, with further subdivisions into stadial and interstadial (Lowe and Walker,

1984; Momer, 1996; Pirazzoli, 1996; Lambeck and Chappell, 2001). It is now acknowledged

that there have been between 30 and 40 glacial/interglacial cycles over the past 2 million

years resulting in global fluctuations of continental ice accumulation and global sea level

(Imbrie et al., 1984; Lowe and Walker, 1984; Peltier, 1999). These repeated changes in

climate have resulted in a complex record of sedimentological, biological and

geomorphological features that provides the clues and data that can be used to reconstruct

past environments.

Glacials

Glacials are major cold episodes of the Earth's history characterised by the expansion of

continental ice sheets and mountain glaciers accompanied by lower global sea level. Glacial

conditions and the development of large continental ice sheets occur when the Northern

Hemisphere receives less summer radiation favouring the persistence of snow into summer

months, leading to persistence of snow cover throughout the year. Once ice sheets are

growing they create a positive feedback mechanism (i.e. self perpetuating) the result of

AQUAs_Submission_to ^Inquiry_into_climate_change_and_environmental_impacts_on_coastal_communities-pm_comments.doc

increased reflection of solar radiation and cooling air around them. This results in an increase

in snow and ice cover maintaining strong latitudinal temperature gradients. During glacial

phases large quantities of ocean water are locked up in the expanding ice caps resulting in a

lowering of global sea levels of up to 130 m.

Stadials

These are cold phases that are shorter than glacial phases and are characterised by

localised expansion of ice. During stadials temperature generaly decline at least halfway

between the warmth of the climatic optimum and the maximum cold of the last glaciation.

This results in fluctuations of sea level in the order of 10's of meters.

Interglacials

Interglacials are warm phases of the Earth's history where temperatures in the mid- and high

latitudes were close to, or higher than, the present average temperatures. During

interglacials the ice caps are significantly reduced in size liberating more water into the

ocean basins resulting in a rising sea level (transgression). We currently reside in one of

these warm phases.

Interstadials

Interstadials are relatively short episodes of warming within a glacial phase. During

interstadials temperature rises to at least halfway between the maximum cold of the last

glaciation and the maximum warmth of the climatic optimum. This also results in fluctuations

of sea level in the order of 10's of meters.

Forcing mechanisms for glacial/interglacial cycles

Switching between glacial and interglacial phases (and their associated stadials and

Interstadials) is, in part, related to the orbital motions of the Earth (the Milankovitch cycles

named after Serbian civil engineer and mathematician Milutin Milankovic). In other words, as

the Earth orbits around the Sun and spins around its axis several quasi-periodic variations

occur. Milankovitch studied these variations and noted that the main changes were in the

Earth's eccentricity, obliquity, and precession. Such changes in movement and orientation

change the amount and location of solar radiation reaching the Earth and have a significant

influence on long-term climate change (Fig. 1).

Earth's eccentricity - 100,000 year cycle

This cycle is determined by changes in the eccentricity of the Earth's orbit around the sun

due to planetary gravitational influences (primarily Jupiter and Saturn). These gravitational

AQUAs Submission to Inquiry into climate change and environmental impacts on coastal communities-pm_comments.doc

influences result in changes in the Earth's orbit from almost circular to mildly elliptical and

back again (Fig. 2; Lowe and Walker, 1984; Williams et al. 1998). The more elliptical the orbit

results in less insolation being received at the Earth's surface and therefore less snow and

ice melt. This change in eccentricity occurs approximately every 100,000 years, and when

these cycles overlap with the other orbital processes (outline below) result in climate

variations corresponding in a peak in global ice and has dominated climate change for the

last 700,000-800,000 years.

Tilt of the Earth's axis - 41,000 year cycle

Dominant prior to, and superimposed on, the 100,000 year cycle is a series of small surges

or decreases in ice volume. This cycle matches the variations in the tilt of the Earth's axis

(obliquity) with respect to the plane of the Earth's orbit which varies from 21.5° to 24.5° and

back over the space of 41,000 (Fig. 2; Lowe and Walker, 1984; Williams et al. 1998). When

the obliquity increases the annual mean insolation increases in high latitudes while lower

latitudes experience a reduction in insolation. This results in cooler summers and less

melting of the previous winter's ice and snow, leading to glacial periods. Presently the Earth

is tilted at 23.5° from its orbital plane, roughly halfway between its extreme values.

Precession - 23/19 ka cycles

Another superimposed cycle was found to

occur between 23 and 19 ka due to the

Earth's precession. Precession is the change

in the direction of the Earth's axis of rotation

relative to the Sun at the time of perihelion

and aphelion. In other words it is the change

in the direction of tilt but the angle of tilt

remains the same. This is also known as

"wobble" (Fig. 1; Lowe and Walker, 1984;

Williams et al. 1998).

Eccentricity Cycle (100 k.y.)

Obliquity Cycle (41 k.y.)

Normal to Ecliptic:(iptic ©scot Buttetford (1997)

Precession of the Equinoxes (19 and 23 k.y.)

i tNorthern Hemisphere tilted away from the sun at aphelion.

Figure 1: Orbital forcing on climate changeadapted from Scott Rutherford and Jerri King,School of Oceanography, URI, Narragansett, 2006

i Ihemisphere tilted toward the sun at aphelion.


Marine isotope record and Quaternary climate change

As many marine organisms secrete carbonate shells and abstract oxygen from saltwater in

the process, the oxygen isotope ratio preserved in the fossil carbonate reflects the ratio of

oxygen in the saltwater at the time of secretion. There is now considerable evidence to show

that 518O (ratio between H216O and H2

18O) in ocean waters varies between glacial and

interglacial cycles. The variations of 518O found in deep sea foraminifera is a result of natural

fractionation of oxygen isotopes during evaporation of water from the sea surface and lighter

H216O molecules are preferentially drawn into the atmosphere compared to the heavier H2

18O.

Accordingly, during glacial phases with expanding ice sheets and glaciers, large quantities of

H216O were trapped in the accumulating ice masses, leaving the oceans enriched in H2

18O

(isotopically positive). In contrast, during interglacial and interstadials periods large volumes

of enriched H216O are liberated back into the oceans as the ice sheets melt, resulting in

lighter 518O ratios (isotopically negative).

Analyses of the 518O record, preserved by deep-sea foraminifera collected from deep-ocean

core from different parts of the world's oceans has verified the presence of these orbital-

forcing influences on long-term climate change and the glacio-eustatic sea-level signal

(Emiliani, 1955; Shackleton and Opdyke, 1973; Imbrie et al., 1984; Chappell and Shackleton,

1986). This indicates that the oceans as a whole have been responding to a common

climatic forcing mechanism (i.e. the Milankovitch cycles). Accordingly, changes in the 518O

isotopic record form the basis for stratigraphic division of individual profiles and the

correlation of late Quaternary sea-level and climate change on a global scale (Fig. 3; Imbrie

et al., 1984; Chappell and Shackleton, 1986). The peaks of the 518O isotope record are given

odd numbers and correspond with interglacial and interstadial sea-level highstands (warm

phases with lighter 518O values). In contrast the troughs observed in the isotopic record are

given even numbers and correspond with glacial and stadial sea-level lowstands (Cold

phases with heavier 518O values; Fig. 2; Shackleton and Opdyke, 1973; Chappell and

Shackleton, 1986; Lambeck and Chappell, 2001).

THE LAST GLACIAL-GLACIAL CYCLE

The last glacial cycle encompasses 130,000 - 17,000 years ago (Fig. 2). This period of time

has been extensively studied with a diverse array of palaeo-environmental records including

the oxygen isotope records from deep sea sediments, high-resolution pollen records, and

lake sediments, gas profiles from ice cores as well as evidence from geomorphological and

stratigraphic data. This period of Earth's history also saw a dramatic fluctuation in

environmental conditions from the warm interglacial with higher than present temperatures

and sea levels to the Last Glacial Maximum (LGM) with colder than present temperatures


and lower than present sea levels. However, most significant in this time period (from a

human perspective) is that this is the period that modern humans (anatomically and

genetically) evolved. Accordingly, due to the wealth of proxy environmental data, various

dating methods appropriate to this time period and the significance to the study of human

evolution the last interglacial - glacial cycle has attracted multi-disciplined research including

geology and geomorphology, ecology, archaeology and anthropology.

Last Interglacial (MIS 5e)

The start of the last interglacial is marked by an abrupt shift from the heavy isotopic values

that characterised Marine Isotope Stage 6 (MIS 6) to lighter isotopic values that reflect glacial

melting. This abrupt shift (a.k.a. Termination II) occurred approximately 130,000 years ago

and provides a marker horizon defining the lower boundary of the last interglacial (Figure 3).

The last interglacial has been divided into 5 oxygen Isotope sub-stages (MIS 5a - MIS 5e;

sensus lato). However, only MIS 5e is now regarded as the true interglacial i.e. sensus strict

(Fig. 2). Globally the MIS5e is characterised by temperatures up to 5°C warmer and sea

surface temperatures as high as 4°C warmer than present temperatures. Globally Sea levels

during the thermal maximum of MIS 5e have been estimated to have been up to +6 m higher

than present. A comprehensive review of Last Interglacial shorelines and chronologies in the

Australian region obtained using various dating methods on in situ mollusc shells from

widespread MIS 5e marine strata has been presented by Murray-Wallace and Belperio

(1991) and Murray-Wallace (1995). Results from these reviews indicated that sea-level

during the Last Interglacial ranged from -2 m around the Great Barrier Reef to +32 m in

northeast Tasmania and, apart from regions influenced by tectonic uplift, the most consistent

datum for MIS 5e maximum sea-level was +2 m.

2.00-

1.00-

o

0.00-

-1.00-

Last Interglacial~~1 sensu stricto

HoloceneLast Interglacial

sensu lato

0 25 50 75 100 125 150 175 200Age (ka BP)

Figure 3: Marine isotope record over the last 200,000 years (modified after Chappell and Shackleton, 1986;Stearns, 1984; Martinson etal., 1987; Potter and Lambeck, 2004).

AQUAs_Submission_to _lnquiry_into_climate_change_and_environmental_impacts_on_coastal_communities-pm_comments.doc

Summary of climate and sea levels following the last interglacial.

The period from the close of the last interglacial (sensus stricto) to the early part of the Last

Glacial Maximum (LGM) was characterised by oscillating climate conditions with the positive

oscillation (interstadials) and the intervening negative oscillation (stadials) corresponding to

the growth of continental icesheets and fluctuations in sea-level that concentrated in a depth

range of 70 to 20 m below present mean sea level. However these fluctuations are

superimposed on a general decline in sea-level leading into the LGM (Fig. 2; Lambeck and

Chappell, 2001; Yokoyama et al., 2001; Lambeck etal., 2000, 2002).

The last glacial phase (MIS 2)

Early in MIS 2 sea-level fell rapidly to between 120 and 130 m below PMSL between 20,000-

22,000 years ago (Fleming et al., 1998; Peliter, 2002; Lambeck etal., 2000, 2002). Although

there appears to be a generalised global sea-level lowstand of approximately -120 m, minor

regional variations have been noted due to the shape and/or volume of oceans, redistribution

of ocean waters in ocean basins, and vertical movements of coastal areas (Fleming et al.,

1998; Potter and Lambeck, 2004).

HOLOCENE SEA LEVEL CHANGE

The termination of the last glacial phase resulted in a global rise in sea level approximately

11,000 years ago (Martinson et al., 1987). However, no single history of sea level rise can be

applied in detail across regions, let alone globally. In fact, the apparent Holocene sea level

records from sites around the world show great diversity in the maximum height relative to

present sea level, and in the timing that these maximum levels represent. The causes for

these regional variations in timing, and maximum levels reached, is a complex interaction of

geomorphic and geological controls. For example, tectonism or volcanic processes, climate,

sediment discharge and/or compaction, tidal changes, local geoid perturbations and isostatic

warping. Regionally and even locally these factors can create vertical changes in the

elevation of the ground, thus offsetting or enhancing changes in sea level. These local

characteristics then need to be considered in relation to predicting variations in melting

histories from the continental ice loads that existed during the Last Glacial Maximum

(Pirazzoli, 1996). The combination of global and local geological, geomorphological and

climatic controls creates a complex and varied sea level history which makes it impossible to

create one accurate global sea level curve.

Regardless of the problems associated with creating a global sea level curve, a generalised

account of the most recent post-glacial marine transgression can be reconstructed that does

indicates a relatively simultaneous pattern of global sea level rise following the

AQUAs_Submission_to lnquiry_into__climate_change_and_environmental_impacts_on_coastal_communities-pm_comments.doc

commencement of deglacialistion at some time after 17,000 years ago (Williams et al. 1998).

This general rise in sea level occurred rapidly, with present sea level being reached between

8,000 and 4,000 years ago.

This near simultaneous sea level rise experienced during the Holocene can be inferred from

the initiation of most Holocene deltas, and in the development of Holocene coral reefs

(Pirazzoli, 1996). For example, most deltaic sequences that we see today began to

accumulate systematically only when the rate of river sediment input overtook the declining

rate of sea level rise (Pirazzoli, 1996). Stanley and Warne (1994) reviewing 36 worldwide

deltas with clearly definable basal, or near basal units, from tropical, temperate and higher

latitude deltas have developed a generalised sea level history from the initiation of Holocene

delta evolution. They have shown that Holocene deltaic evolution on a worldwide basis

reveals that sea level rose rapidly between 18,000 and 10,000 years ago, then decelerating

and approaching present levels between 6,000 and 5,000 years ago (Stanley and Warne,

1994).

Another palaeo-indicator of a generalised PMT is evident in the development of present day

coral reefs that started almost everywhere during the Holocene, when the rate of sea level

rise decreased. For example, at various depths offshore at sites from Barbados, the

tectonically uplifted Huon Peninsula and numerous other locations from the Caribbean to the

Great Barrier Reef, indicated that the initiation of coral reefs began between 10,000 and

7,000 years ago as sea level rise decelerated (Pirazzoli, 1996). Thus, Pirazzoli (1996)

concluded that by 6,000 years ago most of the present deltas and coral reefs systems were

in place.

However, as noted earlier there is significant regional variability due to geological,

geomorphological and climatic variations. In Australia sea level stabilised about 7,000 years

ago whereas in parts of the northern hemisphere sea level stabilised 3,000 - 4,000 years

ago and in some areas the level has never ceased rising, albeit much more slowly.

Nevertheless, rising sea level during the post-glacial marine transgression was responsible

for the formation of deltaic systems, coral reefs and the flooding of river and glacial valleys to

form estuaries and fiords, respectively. The most comprehensive palaeo-sea level

reconstruction in the Australasin region comes from the southeast coast of Australia (Sloss et

al., 2007). Results from that research show that rising sea level during the most recent post-

glacial marine transgression attained an elevation of -10 m by 10,000 years ago and

continued to rise to -5 m by 8,500 years ago. Between 8,300 and 8,000 years ago sea-level

had risen to at least 3 m below present mean sea level and inundated shallow incised valleys.

AQUAs_Submission_to lnquiry_into_climate_change__and_environmental_impacts_on_coastal_communities-pm_comments.doc

Sea-level attained its present level by 7,700 years ago and continued to rise to between 1

and 1.5 m above present levels by 7,400 years ago.

This was followed by a sea-level highstand that lasted to sometime between 3,000 and 2,000

years ago and eventually a relatively slow and smooth regression of sea-level from +1.5 m to

the present level. A series of minor negative and positive oscillations in relative sea-level

associated with variations in ocean topography and/or climate change during the mid- to late-

Holocene appear to be superimposed over the Holocene sea-level highstand and

subsequent smooth sea-level regression. These oscillations in sea-level most likely

represent intertidal species adjustment to variations in coastal exposure and/or variable wave

and climate conditions during the Holocene.

.' Tl

- r p -

O Fixed biological indicators

• Salt-marsh peat and organic-rich rnud

n Marine and estuarine mollusc shells

* in situ freshwater hardwood stumps

" in situ mangrove root

* in situ mangrove root (this study)

* Marine and estuarine mollusc shells intransgressive sandsheet (this study)

Estuarine molluscs shells in back-barrierdeposits (this study)

-13

--15

--17

--21

-23

(A0)

T3

i.a)

o-a

11000 10000 9000 7000 6000 5000 4000 3000Radiocarbon years (cal yr BP)

2000 1000

Figure 4: Revised Holocene sea-level curve for the southeast coast of Australia. The shaded arearepresenting the envelope of relative Holocene sea-level rise based on the a synthesis of previouslypublished data and new data obtained for this study (from Sloss et al., 2007)

AQUAs_Submission_to lnquiry_into_climate_change_and_environmental_impacts_on_coastal__communities-pm_comments.doc

Conclusion:

The climate induced sea level fluctuations during the Quaternary have had a significant

influence on the sedimentation and geomorphic change in the coastal zone over the long and

short term. Most significant is the last full interglacial cycle where dramatic and relatively

rapid fluctuations in sea level have shaped our coast as we know it today. From the

geological record it is evident that there is an intrinsic link between sea level and coastal

environments. It is also evident that although the reasons that sea level change may be

similar there is significant regional variability in sea level histories. We are also now seeing a

period of sea level change that will be more rapid than those documented in our recent

geological past, which will also be subject to significant regional variability. Accordingly, it is

vital that an understanding of how coastal environments responded to sea level (and past

extreme events) on national and regional scales is fundamental when dealing with any

adaption or mitigation programs. Without this historic framework it is impossible to predict

how future changes in sea level and extreme events will influence our coasts environments.

References

Chappell, J. and Shackleton, N.J., 1986. Oxygen isotope and sea level. Nature, 324: 137-140.

Church, J.A., White, N.J., Coleman, R., Lambeck, K. and Mitrovica, J.X., 2004. Estimates of theregional distribution of sea level rise over the 1950-2000 period. Journal of Climate, 17, 2609-2625.

Cutler, K.B., Edwards, R.L., Taylor, F.W., Cheng, H., Adkins, J., Gallup, CD., Cutler, P.M., Burr, G.S.and Bloom, A.L., 2003. Rapid sea-level fall and deep-ocean temperature change since the lastinterglacial period. Earth and Planetary Science Letters, 206, 253-271.

Emiliani, C, 1955. Pleistocene temperatures. Journal of Geology, 63, 538-575.

Fleming, K., Johnston, P., Zwartz, D., Yokoyama, Y., Lambeck, K. and Chappell, J., 1998. Refiningthe eustatic sea-level curve since the Last Glacial Maxiumu using far- and intermediate-fieldsites. Earth and Planetary Science Letters, 163, 327-342.

Imbrie, J., Hays, J.D., Martinson, D.G., 1984. The orbital theory of Pleistocene climate: support from arevised chronology of the marine 180 record. In: Berger, A.L., Imbrie, J., Hays, J., Kukla, G. andSaltzman, B (Eds.). Milankovitch and Climate: Understanding the Response to AstronomicalForcing. Reidel, Dordrecht, pp. 269-305.

Lambeck, K. and Chappell, J., 2001. Sea level change through the last glacial cycle. Science, 292,679-686.

Lambeck, K.,Yokoyama, Y., Johnston, P. and Purcell, T., 2000. Global ice volumes at the Last GlacialMaximum. Earth and Planetary Science Letters, 181, 513-527.

Lambeck, K.,Yokoyama, Y., Johnston, P. and Purcell, T, 2002. Into and out of the Last GlacialMaximum: sea-level change during Oxygen Isotope Stages 3 and 2. Quaternary ScienceReviews, 21, 343-360.

Lowe, J.J. and Walker, M.J.C., 1984. Reconstructing Quaternary Environments. 2nd Edition, Longman,London, pp. 446.

Martinson, D.G., Pisias, N.G., Hays, J.D., Imbrie, J., Moore, T.C. and Shackleton, N.J., 1987. Agedating and the orbital theory of the ice ages: Development of a high-resolution 0 to 300,000-yearchronostratigraphy. Quaternary Research, 27, 1-29.

Morner, N., 1996. Rapid changes in coastal sea-level. Journal of Coastal Research, 12, 797-800.

AQUAs_Submission_to lnquiry_into_climate_change_and_environmental_impacts_on__coastal_communities-pm_comments.doc

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AQUAs_Submission_to lnquiry_into_climate_change_and_environmentaMmpacts_on_coastal_communities-pm_comments.doc

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